Validate a textbox using JQuery

I have TextBox and a Button

first the button is in disabled position When the user starts typing the text in textbox the button should be enabled

How can i achieve this using JQuery or Java Scr开发者_JAVA技巧ipt

Seems like you are a newbie to jQuery. I would say you start with jQuery Tutorials and then move on to jQuery Validate. If you prefer books to start with, you can pick up a copy of jQuery in Action.

you can try with this also

 <input type='text' id='textbox'>
    <input type="button" class="button-disabled" id="change" disabled="disabled" value="click">


    $("#textbox").keyup(checkForm).focus(checkForm);
    function checkForm()
    {
        if($("#textbox").val()=='')
           {
          $("#change").addClass("button-disabled").removeClass("button");
          $("#change").attr("disabled","disabled");
           }
           else
            {
           $("#change").removeClass("button-disabled").addClass("button");
           $("#change").removeAttr("disabled");
            }
       }

<input type='text' id='textbox'>
<input type="button" id="button'" value="click me"> 

$('#button').attr('disabled', 'disabled');

$('#textbox').change(function(){$('#button').removeAttr('disabled')} );

<input type="text" id="myText">
<input type="submit" id="myButton" disabled="disable"/>


jQuery(function(){

jQuery('#myText').bind('keypress',function(e){
    if((jQuery(e.target).val()+"").length>0)
    {
       jQuery('#myButton').removeAttr('disabled');
    }
    else
    {
       jQuery('#myButton').attr('disabled','disable');
    }
});

});

<input type='text' id='thetext' value=''>
<input type='button' disabled='disabled' id='thebutton' value='the button'>

$(document).ready(function(){
   $('#thetext').change(function(){
      $('#thebutton').removeAttr('disabled');
   });
});

Read up on the jQuery API : http://api.jquery.com/

HTML:

<input type='text' id='textbox'>
<input type="button" id="mybutton" value="click me">

JS:

$(document).load(function() {
    $('#mybutton').attr('disabled', 'disabled');
}

$('#textbox').change(function() {
    $('#mybutton').removeAttr('disabled');
}

Update: regarding the use of jQuery w/ ASP.NET, keep in mind that ASP.NET outputs standard HTML once the page is rendered, so the above code would work similarly, except you need to figure out the ID's of the textboxes generated by ASP.net. See this link for further explanation on this:
http://www.search-this.com/2009/08/06/using-jquery-with-asp-net-controls/